1. Field of the Invention
This invention relates to apparatus and methods for the purification of water, and more particularly to apparatus and methods for the purification of water for industrial, commercial and sanitary chemical processing.
2. Description of the Related Art
As the world's population increases and as technology simultaneously advances, the need for water becomes greater. A very strong parallel phenomenon is that the pollution of natural resources, water in particular, is becoming of greater concern.
In many industrial, commercial or public situations where water is used to clean, process, or transport products, conservation of water is of paramount importance. Washing of vehicles, cleansing of processed parts or cooling of air, products or equipment are typical examples of situations requiring conservation of water. In the case of water used for cooling, processes such as condensation, refrigeration, atmospheric evaporation or heat transfer are frequently used. In the case of water used for washing or cleansing, some form of filtration is common to avoid excess disposing of the dirty water.
In certain industrial, commercial and sanitary uses of water to wash parts of coatings or chemicals, the removal of the impurities from the water is difficult. An example of the sort of chemical processing which utilizes large amounts of water to wash the parts both before and after processing is the plating industry. In fact, over 50% of the process steps in plating involve rinsing, and, the cleaner the water, the better the rinse. There are situations in the plating industry in which the quantity of available supply water may be unacceptable to use in plating rinses because of contamination. Cleansing of parts prior to plating is often done with various surface preparation baths, and those parts are normally washed again in clear water prior to plating. After plating, a washing is done to remove excess coating materials. In the first case the rinse water becomes acid or alkaline, and in the second case the water accumulates metal deposits, which may be toxic. In the tradition of the industry, the rinsing water is treated and drained to a sewer. This practice is considered to be both environmentally and economically unsound. In addition to the waste of large volumes of water, significant amounts of metal scrap is being lost.
An attempt to purify water for use in applications such as in the plating industry has been disclosed in U.S. Pat. Nos. 4,563,286 and 4,655,933 to Johnson et al. The Johnson et al. patents recognize that an ionized oxygen molecule will attach to larger molecules and cause a coagulation, or flocculation, to increase the size and improve the filtration efficacy. Johnson et al. employ a magnetic field in combination with an ultraviolet radiation source to generate the ionized oxygen. While the principles of the Johnson et al. disclosures pertain to the problem addressed by the present invention, the method applied to the problem is different, the result achieved deals with only one aspect of the problem, and the Johnson et al. teaching has been found to be inadequate for the commercial needs of the industry.
In particular, it has not heretofore been known in the field of water purification to employ an especially aggressive form of oxygen, known as singlet, or nascent, oxygen, to cause finer particles in the water flow to acquire a charge and to further use a charged electrode in the flow path to agglomerate the finer particles into a larger mass which, when the polarity of the electrode is reversed, is readily removed from the water by a final filter.
It is therefore an object of this invention to provide a water purification system capable of removing suspended and dissolved particulate matter in process water, making it suitable for reuse, while maintaining product quality and production as previously obtained only when using fresh water.
A further object of this invention is to provide a water purification system capable of preventing the waste of industrial, commercial or sanitary process water through effective recycling.
Other objects and advantages will be more fully apparent from the following disclosure and appended claims.